1. Field of the Invention
The present invention relates to static inverters by which electrical energy in the d.c. form is converted to electrical energy in the a.c. form through non-moving or static means. More particularly, the invention relates to transformers suitable for use in such inverers. Such transformers are designed to work in conjunction with a pair of alternately switched semiconductor devices connected in series with the primary winding of the transformer and producing an a.c. output in the transformer secondary. Additional feedback windings are usually present for control of the switching devices.
2. Description of the Prior Art
Known inverter transformers having windings for controlling the associated switching devices. These usually provide positive feedback either to generate oscillations or to square the output waveform. In such cases the effect is normally accompanied by driving the cores into saturation. If the cores are driven into saturation, the magnetizing reactance of the primary windings fall and in consequence the switching devices, if given a continuing forward bias, may be greatly overstressed. In the aforementioned patent application, it was proposed to sence saturation in a portion of the full core cross-section so as to terminate the drive on the switching devices prior to full core saturation and avoid the stressing. The transformer therein described utilized conventional c cores, one of which required an aperture be formed in one of the arms. Available cores lack an aperture designed for such use, and forming such an aperture is a particularly laborious procedure if it is done after the core has been sintered. In addition, the serial insertion of a winding through an aperture is a relatively slow and tedious process.